Cancellation of grating lobes in scanned linear antenna arrays using genetic algorithm.

Abstract

Genetic algorithms have been applied for null steering to control grating lobes in scanned arrays. Element position perturbations and complex-weight variations are the two techniques used for null steering. The use of genetic algorithm for null steering provides grating lobe control at the specified directions. Further control of the grating lobe has been achieved by the appropriate choice of the element pattern of finite length dipoles. Results presented for both uniform and non-uniform arrays, using the GA based control as well as control based on element pattern synthesis show that when these techniques are combined, good radiation patterns are obtained. The research has also shown that by controlling grating lobes, the directivity and the useful scanning range of the array increases. Null steering to control grating lobes does not affect the main beam. It is thus concluded from this research that the genetic algorithm can be an effective tool for designing scanned arrays with controlled grating lobes.